Influence of TCO and a-Si:H Doping on SHJ Contact Resistivity

Resistive losses in silicon heterojunction (SHJ) solar cells are partly linked to transport barriers at the amorphous silicon/crystalline (a-Si:H/c-Si) and transparent conductive oxide (TCO)/a-Si:H interfaces. A key parameter is position of Fermi-level on either side junction which we modify by a systematic doping variation oxide. We identify charge carrier concentration be main driver for low contact resistance. For a-Si:H, this achieved using sufficient but not too high gas during deposition. indium tin (ITO) aluminum zinc (AZO), no or only very oxygen (O 2 ) deposition needed. show that stack low-oxygen ITO interlayer an oxygen-rich “bulk” layer effective means combine efficient TCO absorption also improve thermal stability a-Si:H/TCO/metal resistivity (? c ). Such helps relax constraints regarding optoelectrical performance improves efficiency SHJ cells.